Can someone please explain to me how I sent my eth through a smart contract (via Coinbase)?

I made a transfer of eth from my Coinbase account to Bybit exchange. After it did not post within an hour, I contacted Bybit support and they informed me that:

"Using your account’s ETH wallet address, a quick check on Etherscan determined that your ETH coin was transferred using Smart Contracts. Please note that Smart Contracts transfers are not automatically processed on Bybit and our system only automatically credits ETH Direct Transfers into our traders’ Bybit accounts"

OK, fair enough. I just am trying to understand what happened. Like I said, I transferred this money out of Coinbase, seemingly in the same exact manner in which I transferred the funds last time between these two addresses with no issue.

Maybe this is better off in the Coinbase sub, but what exactly did Coinbase do? I looked at Etherscan and the address from which it came transferred a large sum.

Can someone please explain to me, conceptually, what took place when my funds were transferred via a smart contract? Again, my last transfer between these two accounts was posted within minutes.

Are they just batching withdrawals using a contract?

Thanks.